OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR c++/51406 ([c++0x] Incorrect result of static_cast to rvalue reference to base class.)

Browse Source 
PR c++/51406
	PR c++/51161
	* typeck.c (build_static_cast_1): Fix cast of lvalue to
	base rvalue reference.

From-SVN: r182322
This commit is contained in:
Jason Merrill 2011-12-14 00:18:39 -05:00 committed by Jason Merrill
parent c990877a41
commit 58fc93fb00
5 changed files with 57 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gcc/cp/ChangeLog
View File

@ -1,3 +1,10 @@
2011-12-13 Jason Merrill <jason@redhat.com>
PR c++/51406
PR c++/51161
* typeck.c (build_static_cast_1): Fix cast of lvalue to
base rvalue reference.
2011-12-13 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/51464

16
gcc/cp/typeck.c
View File

@ -5856,12 +5856,22 @@ build_static_cast_1 (tree type, tree expr, bool c_cast_p,
cv2 T2 if cv2 T2 is reference-compatible with cv1 T1 (8.5.3)." */
if (TREE_CODE (type) == REFERENCE_TYPE
&& TYPE_REF_IS_RVALUE (type)
&& lvalue_or_rvalue_with_address_p (expr)
&& real_lvalue_p (expr)
&& reference_related_p (TREE_TYPE (type), intype)
&& (c_cast_p || at_least_as_qualified_p (TREE_TYPE (type), intype)))
{
expr = build_typed_address (expr, type);
return convert_from_reference (expr);
/* Handle the lvalue case here by casting to lvalue reference and
then changing it to an rvalue reference. Casting an xvalue to
rvalue reference will be handled by the main code path. */
tree lref = cp_build_reference_type (TREE_TYPE (type), false);
result = (perform_direct_initialization_if_possible
(lref, expr, c_cast_p, complain));
result = cp_fold_convert (type, result);
/* Make sure we don't fold back down to a named rvalue reference,
because that would be an lvalue. */
if (DECL_P (result))
result = build1 (NON_LVALUE_EXPR, type, result);
return convert_from_reference (result);
}
/* Resolve overloaded address here rather than once in

7
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,10 @@
2011-12-13 Jason Merrill <jason@redhat.com>
PR c++/51406
PR c++/51161
* g++.dg/cpp0x/rv-cast3.C: New.
* g++.dg/cpp0x/rv-cast4.C: New.
2011-12-13 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/51464

17
gcc/testsuite/g++.dg/cpp0x/rv-cast3.C Normal file
View File

@ -0,0 +1,17 @@
// PR c++/51406
// { dg-do run { target c++11 } }
extern "C" int printf(const char *,...);
extern "C" void abort();
struct A { int a; A() : a(1) {} };
struct B { int b; B() : b(2) {} };
struct X : A, B {};
int main() {
X x;
int a=static_cast<A&&>(x).a;
int b=static_cast<B&&>(x).b;
// printf ("%d %d\n", a, b);
if (a!=1 || b!=2) abort();
}

13
gcc/testsuite/g++.dg/cpp0x/rv-cast4.C Normal file
View File

@ -0,0 +1,13 @@
// PR c++/51161
// { dg-do compile { target c++11 } }
struct A{};
struct B : A{};
struct C : A{};
struct D : B, C{};
int main()
{
D d;
static_cast<A &&>(d); // { dg-error "ambiguous" }
}